The Al-Si-C phase diagram and its use for microstructural analysis of MMCpand MMCf composite materials

The microstructure and phase composition of metal matrix composites on the base of Al and Al-Si alloys, containing particles or fibres (MMCp, MMCf) of silicon carbide up to 20 wt.%, have been studied. The character of this in teraction depends only slightly on the type of reinforcing elements. Using the literature and experimental data concerning the microstructure and phas e composition of composite materials after prolonged holding at 700, 800, a nd 900 degreesC, the Al-Si-C phase diagram was corrected. The polythermal s ections constructed both for equilibrium and nonequilibrium conditions allo w to analyse the structure formation of MMCp and MMCf composite materials. The irreversible character of the chemical interaction in composite materia ls is often related to the retardation or the complete suppression of some reactions realized only under equilibrium conditions.